Recently, we've been digging into the philanthropy of billionaire John Malone, chairman of Liberty Media, and his wife Leslie. I wrote about the couple's huge $42.5 million gift to Colorado State University to fund regenerative medicine research in animals and human beings. The Malones have also given tens of millions to Yale and Johns Hopkins and their family foundation supports scholarships at 50 private schools nationwide. Malone is worth $7.3 billion and while he and Leslie haven't signed the Giving Pledge, Malone has said most of his wealth will go to philanthropy.

It isn't too much of a surprise that John Malone is the largest individual landholder in the country, according to the Land Report, and that some of this land is used for conservation and preservation. This part of the Malone couple's philanthropy appears to be influenced by friend and fellow media billionaire Ted Turner, who held the No. 1 spot on the Land Report's list for 15 years before being surpassed by Malone.

The Malones own at least 2.2 million acres in the United States, a mix of crop land, ranch land and woodland, amounting to three times the size of Rhode Island. Much of this land is in the west and northeast. The couple also owns 100,000 acres in South America. What's interesting is that this "land grab" by Malone is relatively recent. The Malones didn't make their first big splash in the area until 1999, when they bought the 80,000 acre Silver Spur Ranch in Saratoga, Wyoming. Around the same time, Malone visited some of Turner's holdings, and his interest in the area really took off.

It's unclear how much money is flowing to conservation efforts through the Malone Family Foundation, but Malone has said that all the land the couple owns will go into the Malone Family Trust, to be preserved forever as open space. Malone also sits on the board of the Nature Conservatory Colorado chapter.

In recent years, the couple purchased an island in Maine and put it under a conservation easement, and funded the protection of the large St. John's River drainage. He's also teamed up with billionaire Craig McGraw in preserving 18 million acres of wilderness and tribal land in British Columbia. In Colorado, the Silver Spur Ranch is a large commercial cattle operation staffed by conservationists and land stewards. The couple has also funded a conservation easement on a 21,000-acre ranch.

It's also worth noting that Leslie has a passion for horse dressage and founded Harmony Sporthorses on land the couple owns in Kiowa, Colorado. Harmony is an international operation, with horses that have competed all around the world, including in the Olympics. All of this helped fuel the couple's aforementioned gift to Colorado State, fueling medical research for animals like their once injured horse.

It's likely that Malone's land acquisition is far from finished, so look for more conservation efforts down the line. It remains to be seen if the Malone Family Foundation will play more of a role in the couple's conservation.